Dentistry

Warning: cinnamon can be harmful to your mouth!

Cinnamon oil contained in chewing gum, toothpaste, pastries, soft drinks, mouthwash and other ingestable products can cause lesions in the mouth. “This is a little known oral health problem,” explains Adel Kauzman, Professor of Pathology at the Université de Montréal’s Faculty of Dentistry.

According to the encyclopedia Pharmacia Diagnostics, cinnamon aldehyde, the oil used in industrial processes, is a “powerfeul irritant” that can be linked to "stomatitis or contact dermatitis, glossitis, gingivitis, perioral dermatitis and hypersensitivity." Moreover, its allergenic effects have been confirmed in animals and humans.

Although these allergic reactions are generally benign and disappear as soon as the patient stops using the product, they can sometimes get worse and cause clinical problems.

While dentists can go several months without seeing a single case of stomatitis caused by cinnamon, they can see many patients in just a few weeks with the symptoms associated with this condition—ulcers, white lesions, inflammation of the gums or of the jugal mucosa. According to Dr. Kauzman, practicing dentists are not always aware of the damage caused by cinnamon oil and don’t always make the connection between the use of this spice and mouth lesions in their patients. But since studies on the subject are rare, it is difficult to evaluate the incidence of this type of affliction. “One thing is sure, it’s a good reason to ask to see a specialist in oral medicine,” says Dr. Kauzman, who points out that cinnamon is widely used today.

The use of cinnamon oil is not a recent phenomenon. Dried and crushed cinnamon bark (cinnamomum zeylanicum) has been used for over 5000 years for its perfumed scent and delicate taste. In addition to its use in the food sector, cinnamon is also employed by the cosmetic industry and by pharmaceutical companies to flavour certain medications.

In dermatology, cinnamon is recognized as the cause of various forms of dermatitis among bakers and pastry chefs who handle the spice everyday. During the course of a study conducted in 1984 among 40 workers from the cinnamon industry, British researchers discovered that 87% of them had symptoms related to the handling of this pungent substance. Nearly one-quarter of the research subjects suffered from asthma and half from skin irritations.

Contact stomatitis refers to inflammation and lesions in the mouth. The patients Dr. Kauzman has seen showed lesions along the curve of occlusion (where the teeth touch) and on the gums. This would suggest that the source of the problem is either a chewed product, such as gum, or an oral hygiene product. Other lesions are more diffuse and therefore harder to identify. Sometimes patients must be referred to a dermatologist for allergy patch tests.

In collaboration with his colleague, Dr. Peter Chauvin of McGill University, Dr. Kauzman decided to examine this question in depth and to set up a research project based on a study of 14 well-documented clinical cases involving patients referred by dentists in private practice in the Montreal area. Dentistry student Jessy Allaire will also take part in the study. The team’s objective is not to ban cinnamon from everyday consumption, but rather to raise awareness, especially among dentists, of the risks associated with its use.